Portal systemic encephalopathy presenting with dressing and constructionalapraxia

We report a case with portal systemic encephalopathy who presented with dre ssing and constructional apraxia and subtle weakness of the left hand. We i nitially suspected a cerebrovascular attack in the right cerebral hemispher e, but brain T-1-weighted magnetic resonance (MR) imaging revealed high int ensity in the basal ganglia and hyperammonemia was detected. We performed a bdominal MR angiography, which visualized an intrahepatic portal systemic s hunt. Cerebral blood flow measured by xenon-enhanced computed tomography, w as decreased in the bilateral, but more dominantly right-sided, parietal wa tershed regions. We speculate that these boundary territories might be susc eptible to damage by toxic metabolites of hepatic encephalopathy.